PETERSON, KLAWE, and SHARP: MERCURY IN TUNAS 



levels in specimens taken in 1971-72 do not 

 differ significantly from those in the same 

 species captured in the same area 85-90 yr 

 ago (Barber, Vijayakumar and Cross, 1972). 

 Also, mercury levels in eight fish, between 

 1605 and 2100 yr old, discovered in Michigan 

 and Illinois archeological sites, were found to 

 be as high as 0.515 ppm; and nine marine 

 fish from a pre-Inca site in Peru contained 

 as much as 9.5 ppm (Medical World News, 

 1972). 



By way of comparison, mercury levels of 

 some other selected marine fishes are shown 

 in Table 2. These data seem to support the 

 general concept that larger predatory fishes, 

 including tunas, have higher mercury levels 

 than those fish species which occupy a lower 

 level in the food chain. 



RELATIONSHIP BETWEEN 

 MERCURY LEVELS AND FISH SIZE 



Swedish investigators (Johnels et al., 1967) 

 reported that mercury levels in northern pike 

 increase with the age of the fish. A similar 

 relationship has been reported for freshwater 

 fishes from Wisconsin (Kleinert, 1972). 



Mercury content is also known to vary with 

 fish size in some marine species, e.g., in sword- 

 fish captured off the Atlantic coast of Canada 

 and the United States (Beckett and Freeman, 

 in press), in Pacific halibut, Hippoglossus 

 ste)iolepis, of the North Pacific coast of Canada 

 and the United States (Bernard E. Skud, 

 International Pacific Halibut Commission, pers. 

 commun.), in a benthopelagic morid Antimora 

 rostrata from the U.S. east coast (Barber et al., 

 1972), in spiny dogfish, Squalus aca)ithias, in 

 the Strait of Georgia, British Columbia (For- 

 rester, Ketchen, and Wong, 1972), and in 

 Pacific blue marlin from Hawaii (Rivers et al., 

 1972). 



A similar relationship has also been demon- 

 strated in some species of tunas. One of the 

 most detailed studies (Ivor>' Coast Fisheries 

 Service, 1972)^ is that for 88 yellowfin tuna, 

 Thunnus albacares, captured in the Gulf of 

 Guinea between July 1971 and July 1972 

 (Figure 1). The large amount of scatter in 



■* Ivory Coast Fisheries Service. 1972. La contamination 

 mercurielle des thons. [Mercury contamination in tuna 

 fish.] Ivory Coast Fish. Serv., Abidjan, 5 p. (Engl, transl. 

 by U.S. Embassy, Abidjan, 7 p.) 



Hawaii: 



Squirrel fish, Myripristis arayomus 14 



Red goat fish, Miilloidichihys auriflummu 10 



Bigeyed scad, Trachiirops criimenophthahnus 10 



Mullet, Mugil cephalus 10 



Monterey Bay, Calif.: 



Myctophid, Tarletonbecinici crenularis 29 



Myctophid, Diaphus theta 5 



Pacific saury, Cololabis saira 2 



Northern anchovy, Engraiilis mordax 3 



Oregon: 



Rex sole, Glyptocephaliis zachirus 82 



Petrale sole, Eopsettajordani 94 



Starry flounder, Platichthys stellaliis 42 



Yellowtail rockfish, Sebasles flavidiis 24 



Rougheye rockfish, Sebastes aleiitianus 30 



Lingcod, Opbiodon elongaius 48 



Sablefish, Anuplopoma fimbria 52 



Pacific hake, Merluccius produclus 24 



Arrowtooth flounder, Atheresthes stomias 26 



Spiny dogfish, Squalus acanthias 88 



British Columbia: 



Spiny dogfish, Squalus acaiuhias 206 



Atlantic coast, Canada and United States: • 



Basking shark, Celorhinus maximus 2 



Blue shark, Prionace glauca 14 



Sickle shark, Carcharhinus falcifonnis 4 



Mackerel shark, Lanina nasus 4 



'25-120 



382 



69-190 



101-199 



78-234 



0.10 -0.43 



0.07 



0.21 



<0.05 



0.11 0.09 



<0.05 



0.013-0.096 

 0.032-0.078 

 0.008-0.011 

 0.055-0.076 



0.05 

 0.05 

 0.08 

 0.19 

 0.06 

 0.06 

 0.03 

 0.06 

 0.01 

 0.20 



0.1 



0.03 

 0.40 

 0.75 

 0.62 



-0.24 

 -0.32 

 -0.50 

 -0.53 

 -0.11 

 -0.73 

 -0.65 

 -0.18 

 -0.33 

 -1.14 



-1.96 



-0.14 

 -1.17 

 -3.28 

 -5.43 



0.030 

 0.060 

 0.009 

 0.063 



0.119 

 0.114 

 0.235 

 0.371 

 0.080 

 0.351 

 0.138 

 0.102 

 0.154 

 0.602 



0.08 

 0.70 

 1.43 

 2.08 



Rivers et al., 1972 



Rivers et al., 1972 



Rivers et al., 1972 



Rivers et al., 1972 



Knauer and Martin, 1972 

 Knauer and Martin, 1972 

 Knauer and Martin, pers. comm. 

 Knauer and Martin, 1972 



Ch 

 Ch 

 Ch 

 Ch 

 Ch 

 Ch 

 Ch 

 Ch 

 Ch 

 Ch 



Ids 

 Ids 

 Ids 

 Ids 

 Ids 

 Ids 

 Ids 

 Ids 

 Ids 

 Ids 



and 

 and 

 and 

 and 

 and 

 and 

 and 

 and 

 and 

 and 



Gaffke, 

 Gaffke, 

 Gaffke, 

 Gaffke, 

 Gaffke, 

 Gaffke, 

 Gaffke, 

 Gaffke, 

 Gaffke, 

 Gaffke, 



1973 

 1973 

 1973 

 1973 

 1973 

 1973 

 1973 

 1973 

 1973 

 1973 



Forrester and Ketchen, 1972 



Beckett and Freeman, in press 

 Beckett and Freeman, in press 

 Beckett and Freeman, in press 

 Beckett and Freeman, in press 



Total length. 



607 



